* [toasts] get rid of notify globals, refactor messageToasts for use by entire app
* [remove notify] use arrow func in ajax call
* fix lint + tests
* actually fix tests from messageToast refactor
* add 'test:one' npm script
* debugger
* [toasts] convert bootstrap flash messages to toasts in explore + sqllab
* [toasts][tests] import from right file
* [explore] DatasourceControl to pick datasource in modal
Makes it easier to change datasource, also makes it such that the list
of all datasources doesn't need to be loaded upfront.
* Adding more metadata